The present invention relates to a transmitter for a coded electronic security system, and more particularly to a transmitter which provides a pulse coded output signal unique to a single transmitter in a system employing a plurality of such transmitters.
Security systems for protecting homes and businesses are becoming increasingly popular due to an increase in vandalism and theft. The most commonly used protective systems require wiring of doors and windows in such a manner that the unauthorized opening of a protected door or window activates an alarm. Conventional systems which require extensive wiring and specially designed switching devices are susceptible to tampering and failure, and they are expensive to install.
Heretofore, attempts at using wireless intrusion alarm systems have met with limited success because such systems have been simply designed merely to indicate the presence of an actuating signal at the remote receiver. Any discrimination relating to rejection of other signals also present was provided merely to avoid false alarms. An indication of an alarm generally did not provide an indication of which particular transmitter in a system having a plurality of transmitters had activated the alarm, unless there were a like number of transmitters and receivers each operating on a different frequency within the system.